Simulated stained glass articles

ABSTRACT

A simulated stained glass article and method for its production comprises a sheet of transparent or translucent material having at least one surface provided with an optically distorting characteristic and a thermosetting or thermofluid composition suitably colored and disposed on at least one surface to provide a desired leaded effect.

This is a a continuation of application Ser. No. 630,410, filed Nov. 10,1975, now abandoned.

The present invention relates to simulated stained glass articles andtheir manufacture.

A conventional stained glass article such as a stained glass windowcomprises a plurality of sheet-like glass sections which are heldtogether by strips of lead at their edges, the glass segments oftenbeing of different colours to provide with the shape of the lead strips,a desired decorative effect. Such stained glass articles are, however,expensive to manufacture since the required materials are expensive inthemselves and the production of the articles therefrom requiresconsiderable skill and effort on the part of the manufacturer.Furthermore, such articles do not lend themselves readily to massproduction techniques.

According to the present invention there is provided a method of makinga simulated stained glass article comprising the steps of treating asheet of transparent or translucent material so that at least onesurface has an optically distorting characteristic and applying to atleast one surface thereof a thermofluid or thermosetting compositionsuitably coloured and disposed to provide a desired leaded effect.

The invention also provides a simulated stained glass article comprisinga sheet of transparent or translucent material which has at least onesurface provided with an optically distorting characteristic and athermofluid or thermosetting composition on at least one surfacedisposed and coloured to give a desired leaded effect.

By depositing the thermofluid or thermosetting composition to a suitablethickness, it is possible to provide the leaded effect with athree-dimensional appearance. Furthermore, since unlike earlierproposals where the leaded effect has been provided by deforming thesheet itself, it is not necessary to provide a separate mould for eachparticular required leaded pattern. Rather, since it is possible toapply the lead effect by a screening process similar to silk screening,this invention has the advantage of being able to mass produce multipledesigns of differing size and shape using the same sheet.

The invention will be further described, by way of example, withreference to the accompanying drawings in which:

FIG. 1 is a perspective view partly in section of an embodiment of thepresent invention;

FIG. 2 is a transverse sectional view of the simulated stained glassarticle shown in FIG. 1;

FIG. 3 is a sectional view through a second embodiment of the invention;and

FIG. 4 is a schematic cross-section of one method of providing anoptically distorting characteristic for the simulated stained glassarticle of the present invention.

Referring to the drawings, in which like reference numerals have beenused to denote like parts, FIG. 1 shows a simulated stained glassarticle 10 which comprises a sheet 16 of transparent or translucentmaterial. Sheet 16 is formed from a plastic material such as a sheet ofcellulose acetate butyrate, polycarbonate, polyester, acrylic or clearpolystyrene. These plastic materials are not only relatively inexpensivebut are readily available commercially. For example, cellulose acetatebutyrate sheets are sold under the trademark "UVEX" by Eastman KodakCo., polycarbonate sheets are sold under the trademark "Lexan" byGeneral Electric Co. and polyester sheets are available under thetrademark "Mylar" from E. I. du Pont de Nemours & Co. Acrylic sheets areavailable from American Cyanamid Co. under the trademark "Acrylite",from Imperial Chemical Industries Ltd. under the trademark "Perspex" andfrom Rohm & Hass Co. under the trademark "Plexiglas". The preferredplastic material is cellulose acetate butyrate. Sheet 16 is preferablysufficiently thick for it to be self-supporting, thicknesses greaterthan 0.020 inches being preferred. A typically thickness for sheet 16would be about 0.080 to 0.125 inches, with a typical surface area being4 × 6 feet.

On one major surface 12a of the sheet 16a leaded effect is provided bymeans of a layer 11 of thermosetting or thermofluid composition. Thelayer 11 is suitably coloured to provide the desired appearance forexample bronze, lead, brass, gold, silver, etc. The layer 11 should besufficiently thick to provide the desired three-dimensional effect ofthe leading. A typical thickness for the layer 11 will be in the range1/2 to 3 millimeters, with 2 to 3 millimeters being preferred for mostapplications. The sheet 16 is divided up into panels 13, 14 and 15 bythe layer 11, the panels 13, 14 and 15 being suitably so shaped,together with the layer 11, as to provide the desired decorative patternof the finished article. The colouring of the panels 13, 14 and 15 may,as will be described later, be provided by applying either to thesurface 12a, 12b or both of the sheet 16 coatings or layers such as 13a,14a of transparent or translucent coloured ink. Such coatings or layersof ink may suitably have ultra-violet inhibiting properties and beapplied to either or both surfaces of sheet 16 by silk screening. Thesheet 16 is provided with an optically distorting characteristic for thepanels 13, 14, 15 either before or after the application of layer 11and/or coatings or layers 13a, 14a.

Some of the areas 13, 14 and 15 will be left unprinted by coloured inkso that such areas appear to be the same in colour as the sheet 16which, of course, will usually either be clear or neutral in colour.

It will be appreciated that in FIG. 2 the thicknesses of the layers 11,14a and 13a are not drawn to scale, the thickness of the coloured inklayers 14a and 13a being very much less in comparison with that of thelayer 11 than that shown in the Figures.

FIG. 2 shows a preferred embodiment of the invention in which layer 11is applied to the smoother surface 12a of the sheet 16 and in which theopposite surface 12b is optically distorting in a manner similar to thatof actual stained glass articles. In FIG. 3, the optical distortion isprovided by irregularities on both surfaces 12'a and 12'b of the sheet16'.

In order to enhance the three-dimensional effect of the layer 11 whichproduces the leaded effect it is possible to darken the areas of thesurface 12b or 12'b of the sheet 16 or 16', respectively, which are inregister with the layer 11. This darkening may suitably be achieved byprinting on the surface 12 or 12'b a layer of dark opaque ink by asilk-screening process.

A stained glass article in accordance with the invention may suitably beproduced by one of the five following methods:

1. A transparent or translucent sheet of plastic material having smoothsurface 12a and 12b is silk-screened with one or more ultra-violetinhibiting transparent or translucent coloured inks to provide thedesired design on one or both surfaces of the sheet. The printed sheetis roller coated to provide optically distorting characteristics for oneor both surfaces of the sheet. The leading effect is then applied toeither or both surfaces of the sheet by one of the methods to bedescribed later. If only one of the surfaces is provided with anoptically distorting surface, the leading effect is preferably appliedto the smooth surface. The completed sheet is then cut or die stamped ifnecessary to provide the desired shape and size of the finished article.

2. A transparent or translucent sheet of plastic material having smoothsurfaces 12a and 12b is vacuum or compression formed or extruded so thateither or both surfaces thereof are optically distorting to give anappearance similar to that of "antique" glass. The deformed sheet istrimmed if necessary to provide it with suitably straight edges and ifrequired cut to smaller blanks of varying sizes depending on the endproduct. Then the different coloured panels such as 13, 14 and 15 aresuccessively applied to one or both surfaces of the deformed sheet bysilk-screening. The leading effect is applied by one of the methods tobe described later.

3. A transparent or translucent plastic sheet having smooth surfaces 12aand 12b is silk-screened with one or more ultra-violet inhibitingtransparent or translucent coloured inks to provide the desired coloureddesign on one or both surfaces. Thereafter, the leading effect isapplied to one of the surfaces by one of the methods to be describedlater. The opposite surface of the sheet is then vacuum formed to giveit an optically distorting characteristic. The formed sheet is thensuitably cut or die stamped, if necessary, to provide the required shapeand size of the finished article.

4. A transparent or translucent sheet of plastic material issilk-screened with one or more ultra-violet inhibiting transparent ortranslucent coloured inks to provide the desired design on one or bothsurfaces of the sheet. The thus printed sheet is vacuum formed toprovide optically distorting characteristics for both surfaces of thesheet and is then trimmed. The leading effect is then applied to eitheror both surfaces of the sheet by one of the methods to be describedlater. The completed sheet is then cut or die stamped if necessary toprovide the desired shape and size of the finished article.

5. A sheet is injection-moulded in a mould having a suitably shapedmoulding cavity to provide optically distorting characteristics foreither or both surfaces of the finished sheet. This sheet is thenoverprinted on either or both surfaces with one or more ultra-violetinhibiting transparent or translucent inks and the leading effect isapplied. Thereafter, the sheet is cut or die stamped to provide thedesired shape and size of article. Clearly, since with this method it isnecessay to manufacture a mould which will give the desired opticallydistorting characteristics, the method is more suitable for longproduction runs.

The first method is generally preferred. The roller coating process ofthis method is as illustrated in FIG. 4. The sheet 16 is transportedthrough the roller coating station by conveyor rollers 19 and 20 whichare rotated in the direction of arrows 19a and 20a, respectively. Acoating is applied to the surface of sheet 16 by roller 21. Roller 21typically comprises a core 21a and a casting 21b conveniently formedfrom a room temperature vulcanizing silicon rubber or metal. The surfaceof coating 21b is distorted as shown at 21c. Liquid coating material 22is fed from well or reservior 23 onto the surface of roller 21 and inthe direction of arrow 21d to form coating 24. The roller then transferscoating 24 to the surface of sheet 16 to form distorted coating 25 whichhas a "grain leather" appearance and provides an optically distortingcharacteristic to the finished simulated stain glass article. As will beappreciated, a plurality of rollers can be used to apply and deform thecoating 25. For example, a first roller could be employed having asmooth surface to apply the coating and a second roller having adistorted surface to distort the coating.

The liquid material used to form the optical distorting coating isgenerally clear and plastic such as a resin, epoxy, or an air dryingsilk screening base unadulterated by normal thinners and/or extenders.The liquid material should have a high gloss finish and strongthixotropic properties. In the case of a resin or epoxy, the liquidmaterial should be catalyzed prior to being coated on the roller. Inthis manner a coating of varying thickness and pattern can be depositedwhich can vary in thickness from 0.001 to 0.060 inches, the latter beinggenerally preferred. After the coating has been applied, it is preferredto accelerate the drying time by using blowers or other means which areconventional in the art, particularly in silk screen printing. Since thesubstrate can be printed as shown in FIG. 4 at 13a prior to rollercoating, the optical distorting layer can be used to protect it. Also,as mentioned above, both surfaces of the substrate can be roller coatedif desired to get doubly strong optical distortion. An ultra violetinhibitor can be added to the liquid coating thereby increasing theprotection of the colours in the product to U.V. fading.

The second method is also a preferred method, particularly incombination with vacuum forming rather than compression forming orextrusion. The vacuum forming method is conventional and comprisesheating the plastic sheet to a suitable temperature and then laying orplacing the sheet on the mould which has a distorted or "grain leather"surface. Air is extracted through the holes in the mould so that thesheet is drawn by suction against the distorted mould surface. Thesurface of the sheet in contact with the mould face is thereby distortedwhile the other surface remains substantially smooth. The temperature towhich the plastic sheet is heated before being contacted with the mouldwith depend on the plastic material and thickness, with a temperature of230° to 270° F. being typical for cellulose acetate butyrate, forexample. The mould surface is not normally heated directly and the sheetis typically cooled by circulating air past the sheet with fans whilethe sheet is in contact with the mould.

With all these methods, the sheet may be provided with more than onerepeat of the required design or with multiple designs of varying shapeand size and then the designs separated either by die stamping orcutting after the leading effect has been applied to separate thedesigns.

The layer 11 in FIGS. 1 to 3 which provides the leaded effect in themethods 1, 2, 3, and 5 described above is preferably produced in one ofthe two following ways:

Where a thermofluid composition is used, the thermofluid compositioncomprises a specially formulated hard wax base and fillers appropriateto give strong adhesion to the sheet and also good abrasion qualities.The wax base also contains pigments which give the desired colouring forthe layer 11 so that the produced leaded effect resembles, for example,bronze, lead, brass or silver. The thermofluid composition is suitablyapplied to the sheet to form the layer 11 by passing the compositionthrough a metal screen which has a pattern of apertures thereincorresponding to the desired shape of the layer 11. By making theapertures sufficiently small in relation to the dimensions of layer 11and sufficiently large in number it is possible to arrange a wellcontrolled and even deposition of the layer 11. The thermofluidcomposition will normally need to be heated so that it may be caused toflow through the apertures in the metal screen onto the surface of thesheet and for this purpose an electric current may be passed through themetal screen to provide a heating. The layer 11 is built up by one ormore passes of a pressure member such as a squeegee over the face of thescreen remote from the sheet. During each pass a layer of composition isdeposited on the sheet and hardens virtually instantaneously because ofthe lower temperature of the sheet. It has been found that the layer 11formed in this manner may subsequently soften if the leaded sheet issubsequently subjected to vacuum forming; however, since the compositionhas a high thixotripic quality and surface tension the layer is notcaused to move from its original configuration with careful vacuumforming.

Secondly, the leaded effect of layer 11 may be formed by depositing athermosetting composition on the sheet using a screen similar to thatdescribed in connection with the deposition of the thermofluidcomposition with the exception that no electric current is required.This composition is preferably highly thixotropic, suitable materialsbeing polyester resins or epoxy bases with suitable fillers, should havevery strong adhesion characteristics and resistance to abrasion andtensile stress. Again, suitable pigments may be added to thethermosetting composition to give the desired appearance of the leadedeffect. A catalyst may be added to the composition prior to pouring itonto the metal screen, or other suitable screen, particularly withthermosetting compositions such as epoxy resins which are not airdrying, the catalyst serving to determine the drying time.Alternatively, an air drying highly thixotropic silk-screening ink canbe employed. Again, the layer 11 of thermosetting composition may bebuilt up by successively depositing layers of composition by repeatedpasses, typically two to five, of a pressure member over the remotesurface of the screen, the amount of composition deposited during eachstep being determined by the dimensions of the apertures and gauge inthe screen. As will be appreciated, the thermosetting composition mustbe allowed to dry between the repeated passes of the pressure member.

Several applications of the thermofluid or thermosetting compositionsresult in building up a three dimensional pattern corresponding to andseparating the various coloured sections 13, 14 and 15 with the visualeffect that the coloured sections are individual pieces apparently heldtogether by "metal ridges". A further improvement can be added to thisillusion by finishing the three-dimensional ridges with a brightcontrasting "solder" effect by printing a heavy deposit of such materialat the "joints" of the ridges.

It is sometimes desired to make a simulated stained glass article in anon-planar shape, for example in the form of a cone, part-sphere or tubeas for example, in the case of ornamental lampshades. Clearly, where thesheet forming the article is vacuum formed after the coloured patternsand leaded effect has been applied to it, it is necessary in some casesto "predistort" the pattern of the coloured areas and the leaded effectso that this pattern will be distorted into the desired pattern duringthe vacuum forming operation.

As will be appreciated from the foregoing, the optically distortingcharacteristic of the simulated stain glass article can be providedeither by deforming the surface of the sheet 16 or by deforming acoating applied to a surface of the sheet 16. Furthermore, althoughspecific methods have been described for providing the opticallydistorting characteristic, it should be appreciated that other methodscan also be employed.

What I claim is:
 1. A simulated stained glass article comprising a sheetof transparent or translucent plastic material having two majorsurfaces, at least one of said major surfaces being deformed to distortor refract light incident thereon, said distortion or refraction oflight being caused solely by said deformation of said at least one ofsaid major surfaces, a thermofluid or thermosetting composition disposedon at least one of said major surfaces thereof and coloured to give aleaded effect, said thermofluid or thermosetting composition comprisinga plurality of layers which provide a three dimensional appearance forsaid leaded effect, and at least one coloured ink printed on at leastone of said major surfaces to give a decorative effect between the areasof the sheet having said leaded effect.
 2. An article according to claim1 wherein each ink has ultra-violet inhibiting properties.
 3. An articleaccording to claim 1 wherein the leaded effect comprises either an epoxybase resin containing fillers therein or a polyester resin.
 4. Anarticle according to claim 1 wherein said thermofluid or thermosettingcomposition is disposed on said at least one deformed major surface. 5.A simulated stained glass article comprising a sheet of transparent ortranslucent plastic material having two major surfaces, both of saidmajor surfaces being deformed to distort or refract light incidentthereon, said distortion or refraction of light being caused solely bysaid deformation of said both of said major surfaces, a thermofluid orthermosetting composition disposed on at least one of said deformedmajor surfaces thereof and coloured to give a leaded effect, saidthermofluid or thermosetting composition comprising a plurality oflayers which provide a three dimensional appearance for said leadedeffect, and at least one coloured ink printed on at least one of saidmajor surfaces to give a decorative effect between the areas of thesheet having said leaded effect.
 6. A simulated stained glass articleproviding a plurality of decorative panels separated by a leaded effectcomprising a sheet of transparent or translucent plastic material havingtwo major surfaces, at least one of said major surfaces being deformedto distort or refract light incident thereon, said distortion orrefraction of light being caused solely by said deformation of said atleast one of said major surfaces, a thermofluid or thermosettingcomposition disposed on at least one of said major surfaces thereof andcoloured to give a leaded effect, said thermofluid or thermosettingcomposition comprising a plurality of layers which provide a threedimensional appearance for said leaded effect, said thermofluid orthermosetting composition dividing up said sheet into a plurality ofpanels, and at least one coloured ink printed on at least one of saidmajor surfaces to give a decorative effect to said plurality of panels,said at least one coloured ink providing a plurality of differentdecorative effects for said panels.